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The total radiant energy per unit area, ...

The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of radius r, whose outer surface radiates as a black body at a temperature TK is given by –

A

`(sigmar^(2)T^(4))/(R^(2))`

B

`(sigmar^(2)T^(4))/(4pir^(2))`

C

`(sigmar^(4)T^(4))/(r^(4))`

D

`(4pisigmar^(2)T^(4))/(R^(2))`

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